Waterproof watch crown



Sept- 1949- c. B. GREENBERG WATERPROOF WATCH CROWN Filed March 17, 1949I u 1 w [Zfll'f fieem ezy I N V EN TOR.

ATTORNEY Patented Sept. 20, 1949 fihai les B. Greenberg, New-ork,;N-.Y., ass'ign or :A'lig'r'en Watch Findings ooflnamew'york,

ApplicationMare'h H, 1949,7Serial2No. 81:858

invention relatesto watch crowns, and more particularly, to waterproofwatch crowns editable for use with watch cases having protecti tubes.

application 'for apatent is acontinuatienj'in part of my applicationentitled Waterproof watchfcr'owns;

no inoisture or dust protection is provided.-

variation 'is due to non unifcrmity in the s'i'ze'hf tlie'wa't'chcase'tubes and the bores-of the crown packing, and to variations-inthaphyslcal properties of the packing,

istherefore an object of this invention to provide a waterproof --c'1ownwhose "fit with a watch case tube can be regulated or adjusted to give"any definite 'desired degree of tightness without e angi ng any of thevdlmensionsofthe eieine'ntscfthe crown or of the watch ease'tube.

Examinations of waterproof crowns of the usueronstrueuon have shown'thatnon-uniform gripping lprssu're between the contacting faceshecfownpacking and the watch case tube fiequenuy "result in 'a packing"being torn apart,

split "or "e'iicessively'wor'n or abraded and ultimately results in thecrown losing its waterproofing characteristic.

"It is an object of 'this invention therefore "to provide means causingthe crown packing to giip'th'e watchcase tube with uniform'intensityth'roug'houttheir entire contacting surfaces,

A shallow, low or small crown "has many artistic advantages over a high,big crown and therefore is in ."fa'regreater demand. l lowever,

shallow and small waterproof crowns used with tiibe type watch cases donot seal-eifectively-lthe case a'gains't moisture, etc., because of thesmall areaoi coiita'etbetween the crown packing arid the when case tube.

Therefore, an object of the invention is "to form a large, high crownpresenting or .givi'n'g the appearance of (a small shallow crown '"and'so having the ;'artistic advantages of "the small crown and theephySiGa]. advantages of 'the larg'e crown.

Another object is to form a shallow or sina'll waterproof crown with arelativly great areaot sealing eontact between the crown .paliing andthe watch case-tube.

. A small waterproof crown which hugs, 'or-res'ts close to -its-case=isespecially difiicult to'mo'v'e'or pull out to allow esetting of thewatch becaus of*-the=tight-gr ip between the crown packing and thecaseand the inability-toobtain a s'eci'ireg rip on=the -crown. "'Thecreation of a finger fgriplb'y the use-of a larger crown or bypositioning the crown away from the case results'inan unsightlyappearing watch and the separated 'o rset 0 ft crown presents aprdblemof increased 'thidiie and bending. 7 'Iherefore, an object of thisinvention "to forma waterproof crown which is "petitea'ndis positionedhugging'the case and alsowhich can be -g;ripped easily and so moved to asetting position.

-A further object is to 'forrn'a 'wate'rproo'fwateh crown of a :minimumof elements which are easily and simply assembled and to .producensightly and easily manipulated 'crown 'c'ap'ab'le withstanding excessivewear and 'cons'ider'atile abuse. A

'I-accomplish these and other "obiectsby forming my crown of acrown"fr'am'e, a fianged'tiibe, and amesilient annular "pack'ingthecrownframe having'acrown Welland aw-ihdi'ng post therein, the flangedtube"'bein'g "fQrce fitteH into the wet andengaging the sides'there'ofsubstantially "for their entire surface area, the 'flange of "the "tubebeingflpositioned at the outer end of the tribe and extendinginwardlytoward the windingpost-of the well and the resilient annularvpackingbeing longer, :When not underpressure, than the depth of the well or"tube and"being'hld'ihposition, under pressure, in the well and aboutits winding post, by the flanged tube 'where'bythe depth positioning ofthe tube-inthe well deter mines the annular diameter '-of the resilient.packing and the intensity of its grip on the watch rcase -tiilie. AIpositioning of the'tube withits outer end pro;

3 truding from the well results in an excess of contact of the packingwith the watch case tube and provides a finger grip for setting thewatch even though the crown is shallow.

For further comprehension of the invention, and of the objects andadvantages thereof, reference will be had to the following description,the accompanying drawings and to the appended claims in which thevarious novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure;

Fig. 1 is a perspective view of a waterproof watch crown embodying theinvention and showing its crown frame, flanged tube, and resilientpacking in full line and a watch case tube in dashed line.

Fig. 2 is a sectional view in two parts, shown,

on the left side, a crown with its tube'flush with its crown frame andwith the resilient packing under a maximum pressure, and on the rightside, a crown with its tube extending above the crown frame and theresilient packing under less than maximum pressure.

Fig. 3 is a fragmentary view of the crown shown in Fig. 2, right side,positioned on a watch (shown in dashed line).

In the drawings and in the specification, in which like numbersrepresent similar elements, a waterproof watch crown I8, is showncomprised of a crown frame H, flanged tube l2 and a resilient packingi3.

The crown frame I! is cup-shaped, having an opening or well I 4 providedwith side walls [5, an a bottom I 6. axially in the well, is providedwith female threads suitable for engaging the threads of a watchmovement stem (not shown).

The resilient packing i3 is positioned in the well about the post andthe flanged tube is force fitted into the well with the flange l8extending inwardly toward the post and exerting pressure on the packing.The sides of the tube which extend substantially to the bottom of thewell are in intimate engagement with substantially the total surfacearea of the walls of the well, so that while the total force of theengagement is great, the unit pressure between the contacting faces issmall. This permits the flanged tube to be inserted and gripped by thecup walls with a mini- 7 More than the normal clearance between thewatch case tube and the flange is needed as there is a tendency for atrailing edge 18 of the resilient washer to adhere to the watch casetube when the crown is moved away from the watch in the settingoperation and this edge becomes wedged between the watch case tube andthe inner edge 20 of the flange. The return of the crown to the watchdoes not release the caught edge I9. This results in an excessive andnon uniform pressure by the packing and causes abnormal wear and makeswinding difficult.

The pressure, created by the flange pushing against the packing, istransmitted longitudinally and laterally throughout the resilientpacking and causes the packing to grip the side walls of A winding postl1, positioned '75 setting.

the tube, the bottom of the well and the watch case tube (shown indashed line) which is inserted into the well, when the watch stem isthreaded into the crown post. Thus the packing forms a closure about thewatch case tube and so shuts and seals off the watch case openingthrough which the watch stem extends.

During the winding operation of a watch provided with the crown ID, atwisting or torque is developed in the resilient packing as the packingrotates with the crown while gripping the watch case tube which remainsstationary, To carry and transmit this torque properly, the packing mustgrip the watch case tube uniformly throughout their area of contact andalso the packing must grip the side walls of the flanged tube uniformlythroughout their area of contact, and both areas of contact must extendsubstantially for the full height and depth of the crown well. Withoutthe uniform pressure and the full areas of contact, there is a tendencyfor the packing to r be twisted and torn. This occurs when one end ofthe packing grips the watch case tube and the other end grips theflanged tube of the crown. In addition, there is a tendency where thereis nonuniform pressure for the packing to wear unevenly and for thecrown to lose its waterproofing characteristic. Uniform pressurethroughout the packing is obtained by providing substantial encasementof the packing within the tube of the crown and that all the pressuresupplied to the packing be in a direction parallel to the axis of thetube.

The total pressure, or the grip of the crown packing about the watchcase tube must be sumcient to provide an effective waterproof seal butmust not be so large as to prevent the Winding and setting of the watch.The ultimate location of the flange of the crown tube, which creates thepacking pressure, therefore, becomes highly important. As all batches ofresilient packing are not of exactly the same resiliency and theresultant packing therefrom cannot have exactly the same inside andoutside diameters and as the specifications of all watch companies forwatches of the same size are not the same for their watch tube elementsa standard location for the flange cannot be set to give the requiredpressure and result in a crown having a good waterproof char acteristicand also being easily wound and set.

In making the crown [0, the variations in the physical properties of thepacking and the dimen sional variations in the watch case tubes areconsidered and the depth to which the flanged tube is inserted in thecrown well is appropriately cor rected to correspond to the diiferentspecifications. Thus, without changing any of the crown frame, flangedtube or resilient packing basic dimensions, a crown is formed which canbe adapted to function perfectly with many sizes of watch case tubes.

The crown 2| (left side of Fig. 2) is shown with its flanged tube 22inserted into the crown well so far that the upper edge 23 of the flangeis flush with the top of the crown frame, while in the crown in (righthand side of Fig. 2) the outer face 24 of the flange of the tube !2extends above the crown frame H.

The setting operation of a watch is made easy by the crown I B as itsextending flange is in close proximity to the watch case, while thecrown frame rests slightly away from the case and thereby provides anopening into which a finger nail can be inserted to retract the crownfor It should be noted that the area of contact between the resilientpacking and the watch case tube is greater in the crown it than in thecrown 2i and as a result, the crown I a) will have a betterwaterproofing characteristic than the crown 2!. A crown developed withan extending flanged tube can therefore be made with a goodwaterproofing characteristic and having its frame of a low height orshallow and so of a sightly and delicate appearance. The extendingflanged tube, therefore, provides a finger grip to aid in setting thewatch and. permits the construction of a shallower, lower and neaterappearing crown.

Although I have shown and described my waterproof crown in its main formand what could possibly be termed a variation, many other variations arepossible without departing from the spirit and scope of the ideasconveyed in the drawing and description; therefore, I desire to coverall modifications, forms and embodiments of my invention coming withinthe scope and language of any and all of the claims here following.

Having thus described my invention, what I claim as new and desire tosecure by United. States Letters Patent is:

1. In a watch crown suitable for use with a tube type watch case, acrown frame having a crown well, a resilient annular packing resting insaid well and a tube having an inwardly extending flange, the tubesubstantially positioned in the well and gripping the major portion ofits wall and the flange exerting pressure on the resilient packing,whereby the packing grips and forms a seal when the crown is applied tothe tube of a watch case.

2. In a crown as described in claim 1, having its flange extending overonly a substantial part of the resilient packing whereby sufficientspace is provided between the flange of the crown and the watch casetube to prevent the packing from becoming wedged therebetween.

3. In a watch crown suitable for use with a tube type watch case, acrown frame having a crown well, a resilient annular packing restingpartially in said well and a flanged tube having an inwardly extendingflange, the tube substan tially positioned in the well and gripping amajor portion of its wall and extending above the upper edge of thecrown frame and its flange exerting pressure on the resilient packing,whereby the packing grips and forms a seal when the crown is applied tothe tube of a watch case.

In a watch crown suitable for use with a tube type watch case, a crownframe having a crown well, a resilient annular packing resting in saidwell and a tube having an inwardly extending flange, the tubesubstantially positioned in the well with its lower end spaced from thebottom of the crown well and said tube exerting a light unit pressureagainst the well wall and the flange of the tube pressing against theresilient packing, whereby the position of the tube in the well can beaccurately adjusted to vary the pressure in the resilient packing.

5. In a watch crown suitable for use with a tube type watch case, acrown frame, a tube and a resilient annular unitary washer, the crownframe having a crown well, the tube having an inwardly extending flangeand the tube being positioned substantially in the well and gripping themajor portion of its wall and the washer being positioned between andexerting pressure against the well bottom and the tube flange therebycreating an internal pressure throughout the washer.

CHARLES B. GREENBERG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,377,625 Greenberg June 5, 1945FOREIGN PATENTS Number Country Date 159,714 Switzerland Apr. 1, 1933

